As known, hot beverage producing machines comprise a water tank, a pump which channels the water taken from the tank into a heat exchanger, which takes the water to a predetermined temperature, and a percolation chamber, in which a quantity of infusion product (in powder form, in a pod, in a capsule) is housed. The water from the heat exchanger reaches the percolation chamber and is mixed with the infusion product herein. The beverage thus formed is then fed from the percolation chamber outside the machine.
For given beverages, such as coffee, for example, users prefer a creamy beverage, and in this case some manufacturers of such machines have adopted systems for mixing the beverage exiting from the percolation chamber with pressurized air. However, such systems are complex because they are made directly in the percolation chamber. It is worth noting that the further channels required to make such systems must be periodically subjected to in-depth cleaning to remove scaling which has formed and which could obstruct the channels themselves. Now, it is apparent that either descaling liquids must be used or the percolation chamber must be removed from the machine to then clean it for such cleaning operations. In addition, in the first case, water must be subsequently made to flow at a given pressure in the channels of the aforesaid systems so as to make any residues of the liquids used to remove the scaling flow out. In the second case, either the machine is taken to a maintenance center with consequent costs or there is the risk of breaking some parts of the machine if the users remove the percolation chamber themselves.